Field of the Invention
This invention relates to cookers for roasting, broiling, smoking or barbecuing meats and more particularly, to a convection meat cooker which uses convection heat to achieve a uniformly heated, high temperature, negative pressure cooking chamber and drastically reduces the time required for roasting, broiling, smoking or barbecuing meats, in such a manner that most of the natural moisture and tenderness is retained in the meat as the meat is cooked. In a preferred embodiment the convection meat cooker is characterized by an elongated, cylindrical cooker tank which, in a preferred embodiment, is horizontally mounted on a portable cooker frame. The cooker tank is constructed from concentric outer, middle and inner shells, the inner shell defining an interior cooking chamber which may be hermetically sealed by a door hinged to the outer shell at one end of the cooker tank. A cylindrical, annular heat chamber is defined between the middle and inner shells throughout the length of the cooker tank, and surrounds the cooking chamber and insulation is typically provided between the middle and outer shells of the cooker tank. A heat entrance port extends outwardly from the middle shell through the insulation and outer shell of the cooker tank and receives a typically propane-fueled burner for directly heating the annular heat chamber, and the cooking chamber is heated by convection from in the annular heat chamber. A heat exit port similarly extends from the middle shell of the cooker tank and vents excess heat from the annular heat chamber and in an alternative embodiment, a damper is provided in the heat exit port to facilitate regulating flow of heat from the annular heat chamber. In a preferred embodiment an open water container is removably attached to the cooker frame and pressure vent piping, provided in fluid communication with the cooking chamber, terminates in a cylindrical pressure vent, the open bottom end of which is immersed in water provided in the water container.
In operation of the convection meat cooker, the meat is initially placed on a meat rack provided in the cooking chamber of the cooker tank and the door is closed and latched to hermetically seal the cooking chamber. As the annular heat chamber is heated by operation of the burner, intense heat is uniformly produced throughout the cooking chamber by convection from in the annular heat chamber, causing a partial vacuum in the cooking chamber and allowing the meat to cook quickly and thus minimizing loss of natural moisture and tenderness from the meat. Excess pressure is vented from reduced in the air-tight cooking chamber through the pressure vent piping, pressure vent and water container, as the cooking chamber is heated. After the cooked meat is removed from the cooking chamber, the burner turned off and the cooking chamber again sealed, the cooling, contracting air in the cooking chamber creates a second partial vacuum which draws moisture from the water container into the cooking chamber, thus cooling and moisturizing the cooking chamber to facilitate wiping and cleaning the cooking chamber interior. A wood holder bracket is typically provided in the cooking chamber above the burner for holding wood or charcoal and smoking the meat, as desired.
Meats such as turkey, ham, roast and chicken are frequently cooked in outdoor grills or smokers to provide a distinct flavor to the meat which cannot be achieved by cooking the meat in an indoor oven or grill. Conventional grills or smokers are typically characterized by a pit in the bottom of the grill or smoker for receiving wood chips or charcoal, gas jets which produce a gas or propane-fueled flame beneath the wood or charcoal and a grill located above the wood or charcoal. These cookers can typically be closed by a lid while the meat is cooking to form a cooking chamber in which smoke and heat from the wood or charcoal is trapped. The cooking chamber is typically not air-tight when closed, however, and this allows escape of some heat from the cooking chamber. Consequently, cooking various kinds of meat can require an inordinately long period of time. Furthermore, the heat is typically not uniformly distributed throughout the cooking chamber, since the heat is applied to the cooking chamber beneath the meat only, and does not surround the meat. This deficiency frequently renders it necessary to open the grill or smoker and change the position of the meat several times during cooking, causing further loss of heat from the cooking chamber.
Description of the Prior Art
Many different types of devices have been designed which utilize a sealed chamber for cooking, processing or maintaining the temperature of cooked foods. One such device is described in U.S. Pat. No. 3,615,599, entitled "Method of and Apparatus for Processing Garlic", dated Oct. 26, 1971, to Yoshizo Sakamoto. According to the disclosed method, garlic is heated and agitated in a closed chamber to facilitate uniform heating under nonoxidizing conditions and obtain the solid and volatile components of the garlic. The volatile component of the garlic is removed from the chamber and separated into liquid and gaseous fractions. As the liquid fraction of the garlic is collected, dust is removed from the gaseous fraction and collected. A "Fruit and Vegetable Processing Apparatus" for continually processing produce such as fruits and vegetables, is detailed in U.S. Pat. No. 4,321,863, dated Mar. 30, 1982, to Peter S. Dimov, et al. The produce is heated by being fed into a pipe coil immersed in hot water and is drawn from the coil by vacuum pressure into an expansion chamber, where the produce is subjected to cold water. The produce is drawn from the expansion chamber with the cold water and then separated from the water. A "Drying Method and Apparatus for Drying Prunes, Fish, Brewers Grain, Shelled Corn, and the Like" which is accomplished by use of a vacuum tank, is disclosed in U.S. Pat. No. 4,326,341, dated Apr. 27, 1982, to Max F. Anderson. The vacuum tank is initially partially filled with cold liquid such as water, and the material to be dried is supported in the tank above the liquid surface. A surface condensing mechanism is located inside the tank adjacent to the tank bottom in the cold liquid and includes a combined vapor inlet-liquid overflow conduit, through which vapor which evaporates from the material to be dried enters and through which liquid in the tank may overflow. Air is evacuated from the tank by first filling the tank with liquid while venting air therefrom, and then pumping the liquid from the tank through the condensing mechanism. Moisture which rapidly evaporates from the material to be dried is condensed at the surface of the cold liquid in the condensing mechanism, and then pumped from the condensing mechanism. U.S. Pat. No. 5,347,918, dated Sep. 20, 1994, to Po-Hung Chen, describes a "Vacuum Thermal Cooker", including an outer cooker, an inner cooker and a sealing lid, which inner cooker is initially used for boiling food and is then placed inside the outer cooker, which is sealed by the sealing lid. The air is then drawn from the outer cooker, creating a vacuum between the outer and inner cookers, such that the food in the inner cooker cannot be cooled by convection of the outside air and can remain heated for a long period of time. U.S. Pat. No. 5,368,872, dated Nov. 29, 1994, to Don M. Davis, Jr., discloses a "Pressure and Vacuum Smoker Apparatus and Method", which apparatus includes separate compartments for maintaining a fire for pressurized smoking of foods and smoking of foods in a partial vacuum. A fire is created in the fire compartment and the food to be smoked is placed in the other compartments. The design of the device enables a user to pressurize the fire compartment with air and to transfer the pressurized and smoke-filled air to the pressure smoking compartment and smoke the foods contained under pressure therein. The design further allows a user to create a partial vacuum in the vacuum smoking compartment, to draw smoke filled air from the fire compartment into the vacuum smoking compartment and to maintain a partial vacuum in the vacuum smoking compartment. Accordingly, the temperature, smoke concentration and pressure in the pressure and vacuum smoking compartments can be regulated. A "High Temperature Wood Smoker" is described in U.S. Pat. No. 5,768,983, dated Jun. 23, 1998, to Rodney Treiber. The smoker includes an outer cooking container for receiving wood chips, an inner cooking container for receiving the food to be smoked and a cover for the inner cooking container. The wood chips are ignited in the bottom of the outer cooking container and produce smoke, which flows through apertures provided in the bottom of the inner cooking container, and the ignited wood chips further provide cooking heat for the food provided in the inner cooking container.
An object of this invention is to provide a convection-type, partial vacuum meat cooker which reduces the time required for cooking food, particularly meat, as compared to conventional meat cookers and smokers.
Another object of this invention is to provide a convection-type meat cooker which uses convection heat to achieve a uniformly heated, high temperature cooking chamber having a partial vacuum, that drastically reduces the time required for cooking meat in such a manner that most of the natural moisture and tenderness is retained in the meat as the meat is cooked.
Still another object of this invention is to provide a self-moisturizing and self-cooling, negative pressure convection meat cooker which uses convection heat to quickly roast, broil, smoke or barbecue meats.
Yet another object of this invention is to provide a convection meat cooker which is provided on a portable frame.
A still further object of this invention is to provide a convection meat cooker characterized by an elongated, cylindrical cooker tank provided on a portable tank frame and including concentric outer and inner shells, the inner shell defining an interior, air sealable cooking chamber; a cylindrical, annular heat chamber defined between the inner and outer shells throughout the length of the cooker tank in surrounding relationship to the cooking chamber; and a burner engaging the cooker tank for directly heating the annular heat chamber, such that the cooking chamber is substantially uniformly heated throughout by convection from the surrounding annular heat chamber during operation of the burner.
Another object of this invention is to provide a convection meat cooker characterized by an elongated, cylindrical cooker tank provided on a portable tank frame and including concentric outer, middle and inner shells, the inner shell defining an interior, hermetically sealable cooking chamber; a cylindrical, annular heat chamber defined between the middle and inner shells throughout the length of the cooker tank in surrounding relationship to the cooking chamber; insulation provided between the middle and outer shells of the cooker tank; and a burner engaging the cooker tank for directly heating the annular heat chamber, such that the cooking chamber is substantially uniformly heated throughout by convection from the annular heat chamber; and a water container provided in fluid communication with the cooking chamber of the cooker tank, such that a first partial vacuum is maintained in the cooking chamber and after the burner is turned off, the food is removed from the cooking chamber and the cooking chamber is re-sealed, the cooling, contracting air creates a second partial vacuum in the sealed cooking chamber, which draws moisture from the water container into the cooking chamber, thus cooling and moisturizing the cooking chamber to facilitate wiping and cleaning the cooking chamber interior.